1. Field of the Invention
This invention relates to an insulator for a terminal-connecting portion to be mounted on or around an ignition coil or a horn of a motor-cycle or the like.
2. Statement of the Prior Art
For convenience of explanation, a prior insulator for a terminal-connecting portion will be described below by referring to FIGS. 24 to 27.
FIG. 24 is a perspective view of a prior insulator A for a terminal-connecting portion, FIGS. 25 and 26 are cross sectional views illustrating the insulator A and FIG. 27 is a front side view of the insulator A. As shown in these drawings, the insulator A includes a hollow L-shaped insulator body 1 made of an elastic material. The insulator body 1 is provided with a female terminal inlet 3 at one end 2 thereof and with a male terminal inlet 5 at the other end 4 thereof. Further, the insulator body 1 is provided with a draining hole 7 having a diameter of 1 mm at an outer corner wall part 6a. A peripheral wail of a curved portion 6 of the insulator body 1 is constituted by the outer corner wall part 6a, an inner corner wall part 6b, and opposite side wall parts 6c.
In this insulator A, a rectangular female terminal 11 connected to a main electrical cable 10 is inserted through the female terminal inlet 3 into the insulator body 1 while enlarging the inlet 3 against its elastic force. At this time, an inner peripheral face of the insulator body 1 closely contacts with three corner parts 11b to 11d, exclusive of a corner part 11a for connecting the main electrical cable 10, out of outer peripheral parts of the female terminal 11, in particular, four corner parts 11a to 11d by an elastic recovery force, thereby holding the female terminal 11 in the insulator body 1. By inserting a male terminal (not shown) connected to a joint electrical cable through the male terminal inlet 5 into the insulator body 1 as shown by an arrow R in FIG. 25, the male terminal is coupled to tile female terminal 11.
In the case that the outer corner part of the curved portion 6 is arranged at a lower position in the insulator A as shown in FIG. 25, rain or the like entering into the insulator A from the terminal inlets 3 and 5 is drained through the draining hole 7 to the outside.
However, since the draining hole 7 is as small as 1 mm in diameter in the prior insulator A, it is impossible to drain the entrapped water due to a surface tension.
In this case, it is possible to drain the entrapped water from a large draining hole 7a which is formed by cutting away the outer corner wall part 6a, as shown in FIG. 27. However, if such a large draining hole 7a is formed in the outer corner wall part 6a of the curved portion 6, the corner part 11d of the female terminal 11 is exposed from the draining hole 7a or in other words the corner part 11d is not protected by the insulator A and consequently the female terminal 11 is supported by only two corner parts 11b and 11c. so that the female terminal 11 is loosely mated in the insulator, the insulator A lowers its terminal-holding ability and the male terminal is hardly inserted into the female terminal. In addition, if the large draining hole 7a is formed in the part 6a. the corner part 11d of the female terminal 11 exposed from the hole 7a interferes with a peripheral portion of the insulator A, thereby causing a short circuit in the terminal.